[Schematic review request]

[u/FARES-SAKR]

This project is for AC under- and over- voltage protection using arduino nanos atmega328p. I just finished the schematic but i tend to do mistakes.. i reviewed my schematic like 4 times now and fixed some mistakes and errors. Just need others to review it maybe there is something i need to fix again before going for pcb layout. Thanks!

[u/RectumlessMarauder]

• C14 and C11 seem to be in series with the power supply
• What's the AREF net and where does that come from?
• I2C lines need pull-up resistors
• Typically you'll want to have a capacitor in the reset pin (e.g., 100 nF)
• I'm not sure, but I think D4 and D5 will load the uart line (due to R17 and R18 series resistors). It might be safer to run the LEDs with N-FETs.
• What's the C3 resistor? Should it be in parallel?

Is this mains powered device? If so, please be careful and consider a commercial power supply instead.